Study data were obtained between August 1998 through December 2000 at three prisons in California: the Substance Abuse Treatment Facility at California State Prison (SATF), Corcoran; the California Rehabilitation Center (CRC); and the R.J. Donovan Correctional Facility (RJD). All of these prisons provide in-custody substance abuse treatment for more than 3 years under the therapeutic community treatment model. They are located within the same geographic area and climate conditions. At SATF the treatment population is segregated from the general custody yards. The study sample consisted of 69 men and 51 women, with the mean age being 35.6 years old. Most of the study participants were correctional officers who had worked in the field between 3 and 6 years. The majority of participants had received some college education. Four measures provided both objective and subjective descriptions of the work environment and participants' perceptions of their physical and psychological health. The study found clear differences in work attitudes of staff between the treatment-oriented and custody-oriented environments. In the therapeutic communities, the staff had a higher level of job satisfaction, fewer occupation injuries, lower rates of staff sick leave, less inmate-on-inmate and inmate-on-staff assaults, and less disruptive inmate behavior. Possible reasons for this are that in the therapeutic communities, more of the staff are involved in dealing with behavior management and behavior shaping, peer pressure, and other components of coping skills. This may render inmates less likely to assault staff members and more likely to use prosocial means of conflict resolution. Treatment custody staff were more concerned about the inmates' feelings, more involved in the open sharing of emotions and thoughts with others, more supportive of inmates' taking prosocial leadership positions, more concerned with practical planning for release, and more supportive of communication between inmates and staff members. 9 tables, 4 figures, 4 notes, and 47 references